English

Countably compact weakly Whyburn spaces

General Topology 2015-11-19 v2

Abstract

The weak Whyburn property is a generalization of the classical sequential property that has been studied by many authors. A space XX is weakly Whyburn if for every non-closed set AXA \subset X there is a subset BAB \subset A such that BA\overline{B} \setminus A is a singleton. We prove that every countably compact Urysohn space of cardinality smaller than the continuum is weakly Whyburn and show that, consistently, the Urysohn assumption is essential. We also give conditions for a (countably compact) weak Whyburn space to be pseudoradial and construct a countably compact weakly Whyburn non-pseudoradial regular space, which solves a question asked by Bella in private communication.

Keywords

Cite

@article{arxiv.1505.06238,
  title  = {Countably compact weakly Whyburn spaces},
  author = {Santi Spadaro},
  journal= {arXiv preprint arXiv:1505.06238},
  year   = {2015}
}
R2 v1 2026-06-22T09:39:52.211Z